<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
#div1 {width:200px; height:200px; background:red; position:absolute; left:0; top:50px;}
</style>
<script>
function startMove()
{
	var oDiv=document.getElementById('div1');
	setInterval(function(){
		var speed=(1000-oDiv.offsetLeft)/10;
		speed=speed>0?Math.ceil(speed):Math.floor(speed);
		
		oDiv.style.left=oDiv.offsetLeft+speed+'px';
		},30);
}
</script>
</head>

<body>
<input id="btn1" type="button" value="开始运动" onclick='startMove()'/>
<div id="div1">
</div>
</body>
</html>
